1. Field of the Invention
The present invention relates to an image forming apparatus such as an MFP (Multi-Functional Peripheral) and techniques concerning the same, particularly, a technique of reducing power consumption.
2. Description of the Background Art
In an image forming apparatus such as an MFP (a so-called complex machine), a power saving mode (e.g., an energy saving mode, a sleep mode) is set for achieving low power consumption.
For example, JP 2007-282117 A discloses an image forming apparatus having a print mode in which the image forming apparatus performs a printing operation, a standby mode (a normal standby mode) in which the image forming apparatus awaits data, and an energy saving mode (a power saving mode) which is lower in power consumption than the standby mode (the normal standby mode). The image forming apparatus shifts to the normal standby mode after performing the printing operation, and then shifts to the energy saving mode when a predetermined shift time is elapsed without reception of a job in the normal standby mode. Thus, reduction in power consumption is achieved.
When receiving an execution request for a job from the outside in the power saving mode, the image forming apparatus returns from the power saving state (the power saving mode) to the normal standby state (the normal standby mode) (or the print mode or the like) in response to the reception of the execution request for the job, and then starts to perform a process of receiving the job, and the like.
However, the image forming apparatus requires a considerable time until the image forming apparatus returns from the power saving state (e.g., the sleep mode) to the state in which the image forming apparatus stands ready to receive the job (the data). Depending on situations, therefore, when receiving an execution request for a job (e.g., a facsimile receiving job) from the outside in the sleep state, the image forming apparatus fails to accept the job in some instances.
With regard to a facsimile receiving job, there exists a technique of receiving and displaying a telephone number (specifically, a facsimile number) of a counterpart (a transmitting side), for example. In a case where the facsimile receiving job is received in the sleep mode (the sleep state), a notification about the telephone number of the counterpart (the transmitting side) has already been provided at the time when the operation of returning from the sleep state is completed, so that the reception of the telephone number is failed in some instances. Particularly, in a case where the image forming apparatus is set so as to determine that a facsimile receiving job is received successfully on condition that a telephone number of a counterpart is acquired, the image forming apparatus fails to receive (accept) the facsimile receiving job.
In order to achieve further reduction in power consumption, preferably, a shift time (a timer period) from the normal state (the normal standby state) to the power saving state (the sleep state) is set to be relatively shorter. However, the short timer period is apt to result in the reception failure described above. On the other hand, when the timer period is set to be longer in order to avoid the reception failure, an effect of reducing power consumption is reduced.